Thanks for posting in the community! I asked the development team for any input here, their recommendation was:
8 cores, 128gb RAM and 2 TB SSD for SQL
From there, monitoring performance and load to determine if you can dial back or need more resources. As every environment is different and the policies/events being monitored for contribute heavily here, it is possible you can start smaller and build up as needed. Ensuring database maintenance is configured and operational is also very important for an environment of this size.